To a question on whether energy conservationists are cautioning against a growing number of buildings with glass façades, which add to global warming, Puri said no such reference has been received by the government.

Glass has its aesthetics and there is no evidence that buildings with glass façades result in extra utilisation of energy, he said.

Puri said the Bureau of Indian Standards (BIS) has issued a Code of Practice for use of glass in buildings in 2019 covering aspects like general methodology for selection, energy and light, fire and loading and safety related to human impact.

The National Building Code 2016 has provisions for use of glass based on their thermal properties to optimise solar load while also taking care of the safety concern in buildings.

Citing a study by IIT Delhi in July 2011, the minister said though glass façade leads to higher energy consumption in buildings, the actual quantum of consumption depends on various factors such as building type, glazing type, glazing orientation and climate type.

The study was titled ‘Suitable glazing selection for glass curtain walls in tropical climates of India’.

The minister was responding to a query on whether a complete glass building consumes electricity four times more than a normal building as per a study done by IIT Delhi.

During the Question Hour, Puri also said that 12 states have adopted the Energy Conservation Building Code (ECBC).